Poll results: How do you deal with the plastic/polythene bags dilemma?

When asked 'How do you deal with the plastic/polythene bags dilemma', 64% of the respondents stated that they reuse plastic bags, 57% use their own shopping bags, 28% store these bags in a kitchen cabinet, and 14% throw these into a waste bin.
None of the respondents burn the bags or throw it into the backyard.

Please participate in the new poll.

Gossamer Webs 1.3

* A new technology for making petrol from carbon dioxide and sunlight. The question, however, is whether this is truly viable.
http://www.newscientist.com/article/dn18993-green-machine-cars-could-run-on-sunlight-and-co2.html?DCMP=OTC-rss&nsref=motoring-tech

* Most of us are aware of how smoking, by pregnant women, can have detrimental effects on the developing foetus. Research by Dr Stephen G Grant of University of Pittsburgh Cancer Institute suggests that ‘similar mutational induction’ may also occur in pregnant women who are exposed to passive smoking. The resulting effects in the babies include birth weight fluctuations, survival, and lifelong susceptibility to diseases such as cancer.
You can download the paper, ‘Tobacco smoke exposure and somatic mutation in newborns’, from http://www.bentham.org/open/topedj

* And another cure from nature: Long-term use of Olive oil results in multiple effects against breast cancer
(paper on ‘Dietary olive oil and corn oil differentially affect experimental breast cancer through distinct modulation of the p21Ras signaling and the proliferation–apoptosis balance’ by Montserrat Solanas, Laura Grau, Raquel Moral, Elena Vela, Raquel Escrich and Eduard Escrich of the Universitat Autònoma de Barcelona, as published in Carcinogenesis)
http://carcin.oxfordjournals.org/cgi/content/abstract/31/5/871?maxtoshow=&hits=10&RESULTFORMAT=&fulltext=Eduard+Escrich+&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT
* A review on the paper published by Anderson et al on ‘Octopuses (Enteroctopus dofleini) Recognize Individual Humans’. Might be of use to fans of Paul the Octopus.
http://cephalove.blogspot.com/2010/07/octopus-sensory-systems-part-25.html

* I am not surprised by the following research (‘Fragrant Dioxane Derivatives Identify β1-Subunit-containing GABAa Receptor’), being someone who often wears jasmine on her hair. Basically, the smell of jasmine is very calming, comparable to that of valium and with absolutely no side-effects!
http://www.jbc.org/content/285/31/23985.abstract?sid=f51dab44-542c-48bf-915e-50b899716064

Man-eating lions and their decision-making

Should one dismiss the past as something of no significant relevance? Well, Justin Yeakel, of the University of California Santa Cruz, and collaborators (from Field Museum of Natural History in Chicago, University of Puget Sound, University of Cambridge, and University of Utah) seems to think otherwise as exemplified by their paper, ‘Cooperation and individuality among man-eating lions’, in the Proceedings of the National Academy of Sciences.

Historical Background
Let’s go back to March 1898 when the British were building a railway bridge across the Tsavo River in southern Kenya. Unfortunately, their progress was hampered by a partnership of two adult male lions, which launched nightly attacks on the rail workers’ camps. This killing spree lasted for nine months, until they were killed by Colonel John Patterson.

The final death toll has always been ambiguous. The first estimate was 28 victims, i.e. the 28 Indian workers who were killed by the lions. But in 1920, Patterson himself revised the death toll to 135, supposedly after factoring in the natives (estimates of which range from zero to 107).

Yeakel’s methodology
To confirm the final death toll, Yeakel used the premise that the Tsavo lions’ diet can be deciphered by analysing the isotopic ratios of nitrogen and carbon in their hair and bone samples (obtained from the Field Museum in Chicago), for it would reflect the isotopic ratios of their prey (i.e. grazing and browsing animals and humans, such as the Taita people who lived in the Tsavo area). More specifically, dietary inputs of the last 2-3 months of the Tsavo lions could be deduced by analysing the hair keratin from the rapidly regenerating tuft hairs of the tail, whilst the lifetime average could be deciphered by analysing the bone collagen. Once this was accomplished, Yeakel modelled the prey combinations which were most likely to produce these distinct isotope ratios.

So, how many?
The final modest estimate was that the lions ate around 35 people. It is likely that the number of humans killed might be greater than the number of humans eaten, for there might have been cases when the lions couldn’t escape with their prey or when the bodies were recovered before the lions could properly sink in its teeth. Perhaps some may have even succumbed to their injuries later.

The Lions’ platter
The results also revealed that, for most of their lives, these lions ate grazing animals- until March 1898. Although they hunted cooperatively (despite hunting humans not really requiring cooperative hunting for they are significantly less hassle than the larger ungulates), there was a disparity in their diets. One lion ate more grazers and some occasional humans (around 11, i.e. approximately 13% of its food intake), whilst the other ate both grazers and humans (around 24, i.e. approximately 30% of its diet). It is quite likely that the latter’s substantial preference for humans had to do with its severe dental problems and jaw injury which may have impeded its ability to hunt.

Why humans?
So why did these lions widen their dietary preferences to include humans?
One possibility was the existing scarcity of the habitual prey, which may have been the result of
i. the Tsavo region experiencing drought in 1898,
ii. unhindered hunting of the lions’ usual prey,
iii. the rinderpest virus (from Europe) which had killed most of the lions’ conventional prey.

Baldus (2006) reports a similar (and fairly recent) case from Tanzania. His previous study (2004) estimated that lions are responsible for one third of the 200-odd humans killed in Tanzania each year by animals (Packer et al states that, between 1990 and 2004, 563 humans were killed and 308 injured by man-eating lions). Nonetheless, from August 2002 to April 2004, a young adult male lion single-handedly killed 35 humans and injured at least 10 in Mkongo Ward, south west of Dar es Salaam. These took place on a thin stretch of agricultural land, along the southern bank of the Rufiji river and enclosed on its western and southern sides by the Selous Game Reserve. Significantly, a human population of approximately 13,000 was residing near the game reserve. But more importantly, the Mkongo lion shared a striking similarity with the dominant Tsavo man-eater: he had a broken upper left molar with a serious abscess. It is likely that, because of the permanent pain, he would have preferred the humans.

Yet, Baldus stresses that most man-eating lions in Tanzania are healthy, with no signs of infirmities. So what transforms the grazer and browser-preferring lion into a human-preferring lion? Fall in the habitual prey densities.

Carnivore-human conflict
Carnivores are forced into conflict with humans when their habitats and habitual prey densities decline (usually due to human related activities such as the creation/expansion/encroachment of agricultural and/or settlement lands, virulent ungulate poaching/hunting) (Hackel 1999; Schiess-Meier et al, 2007). This carnivore-human conflict has resulted in a decline in carnivore population. In 2005, there were only approximately 5,750 Lycaon pictus a.k.a African wild dogs (Swarner, 2004; Lindsey et al, 2005). Cheetah (Acinonyx jubatus) population has fallen from an estimated 30,000 in 1975, to less than 15,000 in the 1990s, the famed Serengeti National Park in Tanzania having just around 200-250 cheetahs (Kelly 2001).

Thus, very likely, it was the change in environmental conditions which changed the dietary specialisations of these lions. What does this bode for the rapidly expanding human civilisation in Africa and Asia? And more importantly, what does this bode for the wildlife population and their natural habitats?

Yeakel, J., Patterson, B., Fox-Dobbs, K., Okumura, M., Cerling, T., Moore, J., Koch, P., & Dominy, N. (2009). From the Cover: Cooperation and individuality among man-eating lions Proceedings of the National Academy of Sciences, 106 (45), 19040-19043 DOI: 10.1073/pnas.0905309106

Baldus, R. (2005). A man-eating lion (Panthera leo) from Tanzania with a toothache European Journal of Wildlife Research, 52 (1), 59-62 DOI: 10.1007/s10344-005-0008-0

**
Hackel, J. (1999). Community Conservation and the Future of Africa's Wildlife Conservation Biology, 13 (4), 726-734 DOI: 10.1046/j.1523-1739.1999.98210.x

Kelly, M. (2001). Lineage Loss in Serengeti Cheetahs: Consequences of High Reproductive Variance and Heritability of Fitness on Effective Population Size Conservation Biology, 15 (1), 137-147 DOI: 10.1111/j.1523-1739.2001.99033.x

Baldus, R. 2004. Lion Conservation in Tanzania Leads to Serious Human-Lion Conflicts. With a Case Study of a Man-Eating Lion killing 35 People. Tanzania Wildlife Discussions Paper No. 41, GTZ Wildlife Programme in Tanzania, Wildlife Division, Dar Es Salaam.

LINDSEY, P., DUTOIT, J., & MILLS, M. (2005). Attitudes of ranchers towards African wild dogs : Conservation implications on private land Biological Conservation, 125 (1), 113-121 DOI: 10.1016/j.biocon.2005.03.015

Packer, C., Ikanda, D., Kissui, B., & Kushnir, H. (2005). Conservation biology: Lion attacks on humans in Tanzania Nature, 436 (7053), 927-928 DOI: 10.1038/436927a

SCHIESS-MEIER, M., RAMSAUER, S., GABANAPELO, T., & KÖNIG, B. (2007). Livestock Predation—Insights From Problem Animal Control Registers in Botswana Journal of Wildlife Management, 71 (4), 1267-1274 DOI: 10.2193/2006-177

Gossamer Webs 1.2

* When the news first emerged of the oil spill off the coast of Louisiana, I ruminated over commenting on this, but it soon morphed into a traumatic topic given the unquantifiable impacts both on flora and fauna. Therefore, here’s an illuminating and succinct insight on the effects of oil spills.
http://whiteswetlands.blogspot.com/2010/06/oil-spills-kill.html

* We read about a catamaran made out of 12500 plastic bottles. And now plans on converting the North Pacific Gyre into a floating island?
http://www.recycledisland.com/

* At least something good has emerged from climate change: The cannibalistic large blue butterfly (Maculinea), which went extinct in the UK in 1979 and is now globally endangered, might be successfully reintroduced because of the rise in temperatures in the Cotswolds- all thanks to the research by Professor Jeremy Thomas (Professor of Ecology and Fellow of New College, Oxford University).
http://www.guardian.co.uk/environment/2010/jun/28/large-blue-butterfly-cotswolds

* Good news for those with hypertension AND a sweet tooth. A meta-analysis by Dr Karin Ried and colleagues reveals that eating chocolates reduces B.P.
http://www.biomedcentral.com/1741-7015/8/39/abstract

* And more on hypertension. Here's another example of how nature always holds the cure for health ailments. A study, by Vikas Kapil, published in Hypertension (‘Inorganic Nitrate Supplementation Lowers Blood Pressure in Humans. Role for Nitrite-Derived NO’ establishes that drinking a glass of beetroot juice per day can dramatically lower blood pressure, and reduces incidences of heart diseases and strokes.
http://hyper.ahajournals.org/cgi/content/abstract/HYPERTENSIONAHA.110.153536v2?maxtoshow=&hits=10&RESULTFORMAT=&fulltext=beetroot&searchid=1&FIRSTINDEX=0&resourcetype=HWCIT

Gossamer Webs 1.1

This is a new series of Our Gossamer Planet posts which will predominantly comprise of links to news articles, posts, and websites which fall under the wide scope of this blog. The chances are that it would be an eclectic mix, but obviously those which will excite your grey cells or make you ponder!

Cats and Toxoplasma gondii

Wiper fuilds and Legionnaire's Disease??? Read on....!

A literal case of butterflies in the tummy. Or is it insects?
Perhaps it is nothing to be squeamish about... after all, some of us do eat prawns (Phylum: Arthropoda; Subphylum: Crustacea)

Erosion- how a canyon was carved in three days!

If you want to listen to the Sun's melody...

Effect of Plastics in Fauna (particularly marine fauna)

A cow and its calf chews a plastic bag in rural Kerala whilst the daily newspaper cites the number of animals which have died after ingesting plastic bags and wastes discarded by the roadsides; A little puppy whines while being trapped in that suffocating cloak; A turtle inquisitively approaches a plastic bag. Indeed, it is very likely that we have either witnessed the above or have seen such photographs.

Now, although I have already referred to the plastic menace in this blog, as well as while highlighting David de Rothschild’s Plastiki in Ecoratorio, this post will focus on the effect of plastics in fauna (particularly marine fauna).

Plastics in marine environment
Due to the increased production (the plastic resin production increased 25-fold from 1960 to 2000) and use of plastics, it is hardly surprising to note the corresponding increase in the quantity of plastic waste entering the marine environment. In fact, 10% of the approximately 100 million tonnes of plastic estimated to be produced per annum have ended up in the marine environments. As a result, 60-80% (90-95% in some areas) of total marine pollution is due to plastics. And this common and persistent pollutant has its disastrous consequences.

Effects in marine fauna: overview
Plastics result in the injury and deaths of hundred thousands of marine fauna per annum (or more, for it is impractical to accurately calculate the number of affected animals in all marine environments), including crustaceans, fishes, dolphins, whales, turtles, seals, and seabirds. As of yet, 267 species of marine organisms worldwide are known to have been affected by plastic debris, a number which is bound to increase after factoring in smaller marine organisms. The fate of all these marine species is hanging in a balance given that they already face other threats to their existence, most notably by other anthropogenic activities. For instance, derelict and/or lost fishing nets have resulted in the deaths of an innumerable number of fishes, birds, and mammals after these get entangled.

What are the threats posed by these plastic bags?
i. Plastics can entangle the marine fauna, oft injuring them, and/or impairing their ability to catch food or avoid predators, and/or drowning them.

ii. Fauna mistake plastic bags and other disintegrated pieces as food, resulting in appalling consequences, with either any or all of the following happening: strangulation, suffocation, abrasions/wounding, poisoning (polychlorinated biphenyls are absorbed), and blockages in the alimentary canal. It is very likely that normal feeding and digestion and/or respiration would be hindered, thus resulting in starvation. The future of these affected fauna certainly seems bleak.

Examples

1. Sharks
Three juvenile Brazilian sharpnose sharks (Rhizoprionodon lalandii), found off the coast of southeast Brazil, featured plastic debris rings around their gill or mouth region. The rings had also caused severe abrasion, which probably increased when the fish grew. Given the emaciated state of two sharks, it is likely that the collars (identified as detachable lid parts of plastic bottles) hampered normal feeding and/or ventilation (study by Sazim et al, of Universidade Estadual de Campinas and Universidade Santa Cecília, 2002).

2. Turtles
The already endangered/threatened turtles mistake the floating, semi-transparent bags for jellyfishes (their primary food), apart from ingesting fishing lines and other plastics. Autopsied turtles have revealed plastic bags in their stomachs, with one notable case off Hawaii turning up around 1000 pieces of plastic, including part of a comb, a toy truck’s wheel, and a nylon rope.

3. Birds
44% of all marine bird species are known to ingest plastic. One study conducted off southern Africa demonstrated ingestion of plastic in 36 out of 60 sampled seabird species.

Albatrosses, fulmars, and procellariiforms oft mistake floating plastics for food or fishes. And the tragic culmination is seen at Midway Island, where out of the 500,000 albatross chicks born each year, 200,000 perish mainly due to consuming plastic fed to them by their parents.

The pattern keeps on repeating. Out of a sample of seven red phalaropes (Phalaropus fulicarius), collected from a flock of 6000 late spring migrants, six stomachs were found to contain plastic particles (by Peter Connors and Kimberly Smith of the University of California at Berkeley).

Plastic was most frequently seen in procellariiforms (notably Blue Petrels, Pintado Petrels, White-faced Storm-petrels, and Great Shearwaters). 90% of examined Blue Petrel chicks at the remote Marion Island, off South Africa, had plastic in their stomachs, again apparently having been fed these by their parents. In another study, the mass of ingested plastic in Great Shearwaters was positively correlated with PCBs in their fat and eggs. When University of Cape Town’s Bridget Furness (1983) sampled bird species in the Benguela Current, small plastic particles were found in White-chinned Petrels and Great Shearwaters. Peter Ryan, also of UCT, established that the size of ingested particles was related to body size, and this affected the proportions of plastic types ingested. Convincing evidence also indicated that although birds generally chose darker-coloured particles over paler particles, the smaller species of birds were less colour-selective and thus correspondingly exhibited a higher incidence of plastic ingestion than the larger species. The incidence of ingested plastic was directly related to foraging technique and was inversely related to the frequency of egestion of indigestible stomach contents. In one of the sampled species, secondary ingestion of plastic through the contaminated prey was important.

4. Cetaceans
26 species of cetaceans accidentally ingest plastic bags, fishing lines and other plastics, which is very much exacerbated when they swallow large mouthfuls of water during feeding. The recent autopsy of a 37-foot long gray whale (in mid April 2010), which came ashore at Arroyo Beach near Seattle, revealed a stomach full of fresh trash, including sweatpants, a golf ball, surgical gloves, duct tape, small towels, bits of plastic, and more than 20 plastic bags. Since these whales are bottom feeders, it is likely that they would unknowingly ingest in these garbage which may have sedimented at the bottom.

Some whale species (such as the reclusive Beaked whale, one of which washed ashore on the Isle of Mull, off the West Coast of Scotland) swallow plastic bags mistaking these for their favourite food, the squid. When the Isle of Mull whale was autopsied, its stomach was seen to contain 23 plastic bags and fragments (some being large dustbin liners and supermarket types).

5. Other
The same pattern is seen amongst the terrestrial fauna. A recent example is that of Whitey, a 10-foot long crocodile in Australia, which died after being relocated to the popular tourist destination of Magnetic Island. It had consumed 25 plastic shopping bags, garbage bags, a plastic wine cooler bag, and a rubber float.

A legitimate concern?
Obviously. The above examples are valid evidences. Furthermore, the gravity of the situation and the extent of the pollution are well exemplified when considering that although the beaked whale feeds 100-200 miles off shore, yet it had a stomach filled with plastic. And the carcharhinid shark species (Sazim et al, 2002) face a great risk since they dwell and reproduce in shallow waters.

Food web and Bioaccumulation
Furthermore, the effect of these pollutants doesn’t end with the demise of the affected animal. The ingested plastics (being non-biodegradable and takes a few good centuries to degrade) remains intact, even after the decomposition of the victim, until it becomes the bane of another animal. The accumulation of plastic debris on the sea floor can also inhibit gas exchange, and disrupt and/or smother the benthic fauna.

In yet another twist (Mato et al, 2001), the floating plastic fragments and pieces acts as sponges, adsorbing hydrophobic pollutants (such as PCBs, nonylphenols, and DDE), and significantly and steadily accumulating these to a high magnitude of concentration. These micro-debris (marine plastic debris < 5mm, usually fragments, resin pellets, and powders) are ingested by filter feeders and/or higher fauna, resulting in the inevitable physiological damages in their bodies. These filter feeders (at the base of the food web) are, in turn, eaten by larger animals- and thus, the food web is contaminated since the pollutants travel up the food chain resulting in bioaccumulation / bioconcentration, i.e the higher up in the food chain, the more an animal is contaminated. For instance, Orcas, which feed on other marine mammals and fishes, are about 10 times more contaminated than gray whales, which usually subsist on crustaceans. <>

Given that some of the cited researches were conducted during 1982-1987, I wonder what will be the nature of the findings if these studies were to be repeated now.
Thoughts, comments, insights, and relevant links are welcomed as always.

Selected references:

CONNORS, P., & SMITH, K. (1982). Oceanic plastic particle pollution: Suspected effect on fat deposition in red phalaropes Marine Pollution Bulletin, 13 (1), 18-20 DOI: 10.1016/0025-326X(82)90490-8
FURNESS, B. (1983). Plastic particles in three procellariiform seabirds from the Benguela Current, South Africa☆ Marine Pollution Bulletin, 14 (8), 307-308 DOI: 10.1016/0025-326X(83)90541-6
LAIST, D. (1987). Overview of the biological effects of lost and discarded plastic debris in the marine environment Marine Pollution Bulletin, 18 (6), 319-326 DOI: 10.1016/S0025-326X(87)80019-X
Ryan, P. (1987). The incidence and characteristics of plastic particles ingested by seabirds Marine Environmental Research, 23 (3), 175-206 DOI: 10.1016/0141-1136(87)90028-6
Mato, Y., Isobe, T., Takada, H., Kanehiro, H., Ohtake, C., & Kaminuma, T. (2001). Plastic Resin Pellets as a Transport Medium for Toxic Chemicals in the Marine Environment Environmental Science & Technology, 35 (2), 318-324 DOI: 10.1021/es0010498
DERRAIK, J. (2002). The pollution of the marine environment by plastic debris: a review Marine Pollution Bulletin, 44 (9), 842-852 DOI: 10.1016/S0025-326X(02)00220-5
Sazima I, Gadig OB, Namora RC, & Motta FS (2002). Plastic debris collars on juvenile carcharhinid sharks (Rhizoprionodon lalandii) in southwest Atlantic. Marine pollution bulletin, 44 (10), 1149-51 PMID: 12474977
CADEE, G. (2002). Seabirds and floating plastic debris Marine Pollution Bulletin, 44 (11), 1294-1295 DOI: 10.1016/S0025-326X(02)00264-3
MOORE, C. (2008). Synthetic polymers in the marine environment: A rapidly increasing, long-term threat Environmental Research, 108 (2), 131-139 DOI: 10.1016/j.envres.2008.07.025

Poll results: Change in Climate

When asked, 'Based on your personal observations, do you believe that the climate in your town/city of residence and/or hometown has changed over the past decade?', 50% stated 'Yes, slightly' and 50% stated 'Yes, severely'.

New poll has been posted.